Lubricating grease



Patented Aug. 16, 1932,

UNITED STATES PATENT orator.

mnnnnrcx w. SULLIVAN, am, am) munrcr: a. nnvason, or Eamon), IN IANA,

ASSIGNOBS '10 STANDARD OF INDIANA LUBBICATING GREASE N Drawing.

This invention relates to alubricating composition and in particular to a lubricant charact'erized by a high degree of hardness and toughness. In the lubrication .of certain types of bearings, particularly large journal bearings, such as are used on rolls in steel mills, it has been common practice to use a solid lubricant or grease of the usual lime tallow soap and mineral oil composition. Be cause of the size of the bearings and the severe nature of the service, the consumption of grease on these bearings is usually quite heavy. Moreover, a stream or spray of water is commonly applied to cool the bearings with the attendant result that water may become emulsified with the grease, causing deteriora tion and loss. It has been found that with harder greases, less is consumed and less wastage occurs. Accordingly, it has been the practice to employ compositions giving greases of maximum hardness. However, when lime-soap greases are made sufliciently K hard, they become friable, and crumble in the bearings, causing increased lubricating difliculties.

We have now discovered a method of making greases of great hardness which are at the same time possessed of a high degree of toughness making them especially suitable for the lubrication of large journals. We

have found that montan wax has the remarkable property of hardeningand toughening the grease in which it is incorporated giving the-coherent products desired. However, in

using this material, it is important that the employ Application filed December 4, 1929. Serial ll'o. 411,871.

The usual practice in making greases consists in reacting all the saponifiable material at once with the base to form a soap in which the oil is then incorporated, In our OH COMPANY, OF CHICAGO, ILLINOIS, A. CORPORATION Example I Per cent Cottonseed foots fatty acid 213 Crude montan wax 10.7 Hydrated lime 3.74 Caustic soda 0.11 Heavy black mineral 'oil 63.0 Water 2.6

, Example [I l i Percent 1 Fatty acid 16.0 Crude montan wax 21.4 Hydrated lime 3. 5 Caustic soda 0.36 Heavy black mineral oil 58. 2 -Water 2. 7

procedure we have found it necessary to depart radically from this method and we combine the above ingredients in the following manner: We first add the lime and the caustic soda to the melted montan wax contained in a grease mixed and then heat to a temperature of about 260 to 300 F. until thoroughly reacted, which may requirefrom 5 to 10 hours.

We then add the fatty acid and continue the heating for a short time, after which the oil andwater are added gradually, the heat beingso controlled that the temperature falls to about F. after all the water and oil are added. During this addition, some of the water is evaporated, so that the finished grease will usually contain somewhat less water than is employed in the formula. The fatty acid which we use may be either of animal or vegetable origin. Fatty acid from cottonseed oil, for example, has been found to be very satisfactory, and we may also use fats such as stearine or lard oil. It is essential that the quantity of lime and caustic soda be carefully controlled so that the grease is practically neutral in reaction, the amount of alkali required varying with the kind of fatty acid employed, the degree of refinement ofthe montan wax, etc. It will be noted that the lime is the chief alkaline constituent of our grease. Caustic soda is employed in small amounts to hasten the saponification of the montan wax, and its action is thought to be principally catalytic. Caustic potash or other strong base can be used to rewe may varythe proportions of montan wax.

and fatty acid over relatively wide limits usually between 5 and depending on the particular properties which we desire in the finished lubricating product. In general, when we employ higher proportions of fatty 25 acid we will employ correspondingly lower proportions of montan wax.. Although we may use refined montan wax, we prefer to use the crude material because of its low cost.

We may also use lower viscosity mineral oils although we prefer using the heavy residual oils. Furthermore, we may add various materialsdesigned to increase the lubrieating power or other qualities of the grease, such, for example, as talc, mica, graphite,

,etc. Thus we may add to the grease, prepared by the above formulae,'from 5 to 30% of flake graphite.

The hardness of the grease can be varied by varying the proportion and the viscosity of the mineral oil incorporated V therein. With lower viscosity oils, i. e., those with viscosities of 85 seconds Saybolt at 210 F. or less, we usually employ a formula with a smaller proportion of oil sometimes as low as 45% of the grease, exclusive of added material such as graphite. When using the heavy mineral oil of the above formulae, having a viscosity of 135 or more Saybolt seconds at 210 F., we may employ as much as 80%.

We also find montan wax to be a useful ingredient in other grease compositions be sides the lime greases described above. Thus we are able to replace a substantial part of r the fatty acid soaps in soda greases with mon- 0 tan waxsaponified with caustic soda. Thls grease has been found suitable for lubrication of bearings which normally run at elevated temperatures, such as railways journals, etc.

An example of the superiority of our im proved lubricant from the standpoint of hardness over that commonly employed, may be seen from the following values obtained by the A. S. T. M. penetration test D525 made at 77 F. Grease prepared according to the formula in Example I gave a penetration test of 27, while that prepared according to the formula in Example II gave a penetration test of 22. In comparison, the

hardest coherent fatty acid lime soap grease which could be made without the montan wax gave a penetration test of 30 or higher.

We have described our invention with respect to both the materials employed and the manner of combining them. We now describe what we consider to benew and essential in the following claims.

l/Ve claim:

1. A solid lubricant comprised of fatty acid, mineral oil, lime, caustic alkali, water and montan wax.

2. The method of preparing a lubricating grease which comprises heating montan wax with lime and caustic alkali until substantially saponified, thereafter incorporating a fatty acid, water and a mineral oil.

3. As a new product of manufacture, a lubriciating composition comprising a mineral oil, a fatty acid lime soap, water, and saponified montanwax.

41 As a lubricating composition, a tough grease comprised of a mineral oil, montan wax and a fatty acid lime soap, having an A. S.- T. M. penetration test of less than 25 5. A lubricating composition comprising about the following ingredients:

6. A substantially neutral grease comprising 5 to 30% fatty acid and 5 to 30% montan wax in the form of their lime soaps, together with .45 to 80% of viscous mineral oil.

7. hard, tough, coherent lubricating grease comprising a viscous mineral oil, a fatty acid lime soap and saponified montan wax.

8. A lubricating grease prepared from fat,

montan wax, lime, caustic alkali, water, and

viscous mineral oil.

9. 'A hard lubricating grease comprising viscous mineral oil and lime soaps of fatty acid and montan wax. 10. A hard grease comprising viscous mineral oil, lime, fatty acid and montan wax incorporated with to 30% of finely divided graphite.

11. The process of making a grease of great hardness and coherence containing montan wax which comprises heating the wax with a substantial excess of alkali until saponified, adding fatty acid suflicient to neutralize substantially. all excess alkali and incorporating a small amount of water and sufficient viscous mineral oil togive a grease of the desiredhardness.

12. The process of mak'ng hard grease which comprises heating from 5 to 30 parts of montan Wax with hydrated. lime and a trace of caustic alkali until essentially saponified, then adding from 5 to 30 parts of fatty acid, to 5 parts of water, and 45 to 80 parts of viscous mineral oil, and agitating the mixture until e homogeneous greese is obtained, the lime and caustic alkali being employed in such amount that the finished product will be essentially neutral.

13. In the process of making a lubricating grease from montan Wax, the step Which comprises saponifying the montan Wax with a substantial excess of alkali end letei" converting the excess of alkali into essentially neutral fatty acid soap.

Signed this 25 dey oi November 1929, at Whiting, county of Lake, State oi Zt'ndiana.

FREDERILGK W.- SULLIVAN, Jn.

A'RVESQN. 

